vanilla vehicles are not corresponding real life. In addons cfgSurface.hpp, there is a values "rough" and "maxSpeedCoef".

If these values are set so that vanilla military cars (quadbike, hunter, ifrit, trider, hemtt, etc.) are still able to move, but only slow, on the surface - the APCs (marshan, gorgon, marid) lose their acceleration and end up stuck.

The APCs should have at least equal or better movement than cars.